Realistic peak: the most your panels can make right now in full sun after real-world losses (heat, wiring, angle) and your calibration. It is lower than the nameplate rating on the panels, which they rarely hit. 100% means you are getting everything your rig can give.
Your panels are rated 3,300 W, but that lab number is rarely reached in the real world, so we scale to what your rig can actually hit.